For example, a technique for reducing the dishing and thinning when the CMP is used to form the metal wiring and the STI (Shallow Trench Isolation) is disclosed in Japanese Patent Laid-Open No. 2002-75932. This technique is characterized in that the polishing pad used in the CMP for planarizing the semiconductor substrate (referred to as substrate hereinafter) includes the polishing pad forming the composite structure with the hydrophilic and water-insoluble polymer and satisfying at least one of the requirements of: (a) the bending elastic modulus is 2 GPa or higher; and (b) the surface hardness is 80 or more of the durometer D hardness.
Also, the technique for preventing the dishing of the metal wiring is disclosed in Japanese Patent Laid-Open No. 2001-358101. This technique is characterized in that the polishing pad used to mechanically planarize the surface of the insulator or that of the metal wiring formed on the substrate satisfies the following conditions: the micro-rubber hardness A is at least 80 degrees; the number of closed cells is in the range of 150/mm2 to 2500/mm2; the density is in the range of 0.6 g/cm3 to 0.95 g/cm3; and the equilibrium water-absorption ratio is 5% or more.
Also, the technique for obtaining the transistor isolation with excellent flatness is disclosed in Japanese Patent Laid-Open No. 8-195435. This technique is characterized in that the polishing liquid obtained by adding alcohol-based amine to coloidal silica to dilute the coloidal silica so that the concentration of the alcohol-based amine is set within the range of 1 to 2% and the polishing cloth with the JIS standard hardness of 85 or more are used, the substrate is polished while maintaining the surface temperature of the polishing cloth or that of the polished substrate not to be cooled but not to exceed 60° C., and after more than three minutes from the start of the polishing, the polishing is finished within three minutes after the temperature of polished surface of the semiconductor substrate reaches the highest temperature.